The present invention relates to automatic dynamic compression/expansion systems, particularly for use in high fidelity sound reproduction equipment.
It is known that the quality of the reproduction of audio frequency performances can be improved by increasing the signal to noise ratio by means of a compression-expansion system known as a compander system, in which the useful signals are compressed in amplitude before they enter a transmission path susceptible to interference, e.g. a line or a recording tape, and are expanded after transmission.
In known systems there is the goal of meeting, inter alia, the following requirements to the maximum extent possible: low cost, corresponding characteristics during compression and expansion, good reproducibility of the required values in instruments of, for example, a mass-fabricated series, and the expandability of the system concept with respect to the selection of the degree of expansion and compression. The known compression-expansion systems are either relatively complicated and produce good quality or they are less expensive -- - as required for instruments sold to the general public -- and do not meet the above requirements to a satisfactory degree.